cmd/gorankusu: implement socket based activation with systemdHEADmaindev

The internal/cmd/gorankusu now can run using systemd.socket(5).

1 files changed, 22 insertions, 3 deletions

diff --git a/internal/cmd/gorankusu/main.go b/internal/cmd/gorankusu/main.go
index 1ede9d4..a55a518 100644
--- a/internal/cmd/gorankusu/main.go
+++ b/internal/cmd/gorankusu/main.go
@@ -7,6 +7,7 @@ package main
 import (
 	"flag"
 	"log"
+	"net"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -17,6 +18,7 @@ import (
 	"git.sr.ht/~shulhan/pakakeh.go/lib/memfs"
 	"git.sr.ht/~shulhan/pakakeh.go/lib/mlog"
 	"git.sr.ht/~shulhan/pakakeh.go/lib/os/exec"
+	"git.sr.ht/~shulhan/pakakeh.go/lib/systemd"
 	"git.sr.ht/~shulhan/pakakeh.go/lib/watchfs/v2"
 
 	"git.sr.ht/~shulhan/ciigo"
@@ -54,11 +56,28 @@ func main() {
 	}
 
 	var (
-		ex  *gorankusu.Example
-		err error
+		listener net.Listener
+		ex       *gorankusu.Example
+		err      error
 	)
 
-	ex, err = gorankusu.NewExample(listenAddress, isDev)
+	listeners, err := systemd.Listeners(true)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if len(listeners) > 1 {
+		log.Fatal(`too many listeners received for activation`)
+	}
+	if len(listeners) == 1 {
+		listener = listeners[0]
+		gotAddr := listener.Addr().String()
+		if gotAddr != listenAddress {
+			log.Fatalf(`invalid Listener address, got %s, want %s`,
+				gotAddr, listenAddress)
+		}
+	}
+
+	ex, err = gorankusu.NewExample(listener, listenAddress, isDev)
 	if err != nil {
 		mlog.Fatalf(`%s`, err)
 	}